A vehicle air-conditioning apparatus is provided which is capable of expanding an effective range of a dehumidifying and heating mode to achieve comfortable vehicle interior air conditioning. A control device (controller) executes a dehumidifying and heating mode to let a refrigerant discharged from a compressor 2 radiate heat in a radiator 4, let a part of the refrigerant flow from a bypass circuit (refrigerant pipe 13F) to an indoor expansion valve 8, and let the residual refrigerant flow through an outdoor expansion valve 6. In the dehumidifying and heating mode, the control device has a state of controlling the operation of the compressor 2, based on a heat absorber temperature Te and executes a radiator temperature priority mode which enlarges a capability of the compressor when heat radiation in the radiator is insufficient.

The invention relates to a refrigerant circuit (1), in particular for use in a vehicle, preferably a motor vehicle, comprising: an air conditioning compressor (2), a main condenser (4), at least one connectable condenser (5), and a switching means (3) which is designed to connect one or more of the switchable condensers (5) to the refrigerant circuit (1), wherein a pressure equalising means (6) is configured to equalise an internal pressure of the at least one connectable condenser (5) with an internal pressure of the main condenser (4).

A method for operating a coolant circuit of a refrigeration system of a vehicle having multiple system sections. A single pressure sensor is located in each system section. A temperature sensor is arranged downstream at each component to be balanced in the system sections, such as heat exchangers and a coolant compressor. The sensor signals of the pressure and temperature sensors are supplied to a control unit for the control or regulation of the refrigeration system. Furthermore, a pressure approximation value at the position of the temperature sensor is calculated by a pressure loss value determined using a pressure loss calculation function starting from the position of the pressure sensor arranged in the system section of the component up to the position of the temperature sensor if the temperature sensor and the pressure sensor are arranged at different positions in the system section.

A cooling system is provided for a traction battery of an electrified motor vehicle. That cooling system includes a cooling circuit, a refrigerant circuit, a plurality of flow control valves and a control system. That control system includes a controller configured to (a) control operation of the plurality of flow control valves and (b) prioritize cabin cooling over traction battery cooling.

Condenser systems for vehicle air conditioning systems and processes for controlling condenser systems are disclosed. The condenser systems include a plurality of fans that can be activated and/or deactivated based on a load indicating parameter of the heat transfer circuit of the air conditioning system.

An air-conditioning control device is provided with: a pressure acquisition unit, that acquires a detection value from a pressure sensor that detects a pressure of a refrigerant flowing through a heat, exchanger; a temperature acquisition unit that acquires a detection value from, a temperature sensor that detects a temperature of a heating medium flowing through the heat exchanger; and a determination unit that, in the case where a command is issued to cause a refrigerant to flow through an opening and closing portion in a state where the refrigerant is not flowing through, the opening and closing portion, determines whether or not the opening and closing portion is normally opened to cause the refrigerant to flow through the heat, exchanger, by using the pressure of the refrigerant detected by the pressure sensor and the temperature of the heating medium detected by the temperature sensor.

The present disclosure relates to a method of controlling a compressor, and may include: pilot driving which drives a compressor of an air conditioner by receiving a start signal; determining whether oil is short which compares the oil amount of the compressor, driven in the pilot driving, with a predetermined reference oil amount; normal driving which maintains the driving of the compressor when it is determined that the oil amount is the reference oil amount or more; and stopping which stops the driving of the compressor when it is determined that the oil amount is smaller than the reference oil amount. Accordingly, by stopping the compressor when the oil is short, it is possible to prevent damage to the compressor.

A method for operating a refrigeration system for a vehicle with a refrigerant circuit including a heat exchanger. A controllable environmental air flow (L) is flowed through the heat exchanger and the heat exchanger can be operated as a refrigerant condenser or a gas cooler for a refrigeration system operation.

Disclosed is a vehicle air conditioning device including a heat pump cycle configured to compress and expand a refrigerant; a heater core; a high pressure side pressure sensor configured to detect a pressure on the high pressure side of the heat pump cycle; and a heater core inlet water temperature sensor configured to detect a temperature of cooling water at an inlet of the heater core as a heater core inlet water temperature. The heat pump cycle includes a compressor; a condenser; a water refrigerant heat exchanger and an evaporator; and a heating expansion valve and a cooling expansion valve. An estimated outside air temperature is calculated based on the high pressure side pressure detected by the high pressure side pressure sensor and the heater core inlet water temperature detected by the heater core inlet water temperature sensor.

An air conditioner for a vehicle includes: a condenser that includes a core for allowing heat exchange between a refrigerant discharged from a compressor of a refrigeration cycle and air; and a switching unit that switches a refrigerant passage in the condenser. The switching unit switches the refrigerant passage between a first refrigerant passage that allows the refrigerant to flow throughout the core, and a second refrigerant passage that allows the refrigerant to flow through a part of the core by allowing the refrigerant discharged from the compressor to flow into a middle part of the core.